Setup, backup, and login are nouns.
Begin Setup
Your login attempt
See Latest Backup
They can also be adjectives:
Setup Assistant
Login Window
Backup Procedure
They are NOT verbs:
I setup my account
First, login here
How can I backup?
Set up, back up, and log in are verbs.
Let’s set up your account
Click here to log in
Back Up Now
An easy way to test for this:
put it in the past tense. If setup was a single-word verb, you would (goofily) say:
I setupped my account.
Next, I loginned.
When I backupped,
These are just three such verbs that include a preposition; there are many more. You know the difference between nouns and verbs. You can do this.
So many apps and websites out there get this wrong (given their focus on such verbs) that I finally sitdowned, rollupped my sleeves, and speakupped in visual form. A sign for me to tap in the future!